Blur detection is unaffected by cognitive load

    Authors

    L. C. Loschky; R. V. Ringer; A. P. Johnson; A. M. Larson; M. Neider;A. F. Kramer

    Comments

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    Abbreviated Journal Title

    Vis. Cogn.

    Keywords

    blur detection; attention; cognitive load; eye movements; retinal; eccentricity; CONTINGENT MULTIRESOLUTIONAL DISPLAYS; DEPTH-OF-FOCUS; N-BACK TASK; WORKING-MEMORY; ATTENTIONAL MODULATION; SPATIAL-RESOLUTION; SCENE; PERCEPTION; VISUAL-ATTENTION; AREA V4; ACCOMMODATION; Psychology, Experimental

    Abstract

    Blur detection is affected by retinal eccentricity, but is it also affected by attentional resources? Research showing effects of selective attention on acuity and contrast sensitivity suggests that allocating attention should increase blur detection. However, research showing that blur affects selection of saccade targets suggests that blur detection may be pre-attentive. To investigate this question, we carried out experiments in which viewers detected blur in real-world scenes under varying levels of cognitive load manipulated by the N-back task. We used adaptive threshold estimation to measure blur detection thresholds at 0 degrees, 3 degrees, 6 degrees, and 9 degrees eccentricity. Participants carried out blur detection as a single task, a single task with to-be-ignored letters, or an N-back task with four levels of cognitive load (0, 1, 2, or 3-back). In Experiment 1, blur was presented gaze-contingently for occasional single eye fixations while participants viewed scenes in preparation for an easy picture recognition memory task, and the N-back stimuli were presented auditorily. The results for three participants showed a large effect of retinal eccentricity on blur thresholds, significant effects of N-back level on N-back performance, scene recognition memory, and gaze dispersion, but no effect of N-back level on blur thresholds. In Experiment 2, we replicated Experiment 1 but presented the images tachistoscopically for 200 ms (half with, half without blur), to determine whether gaze-contingent blur presentation in Experiment 1 had produced attentional capture by blur onset during a fixation, thus eliminating any effect of cognitive load on blur detection. The results with three new participants replicated those of Experiment 1, indicating that the use of gaze-contingent blur presentation could not explain the lack of effect of cognitive load on blur detection. Thus, apparently blur detection in real-world scene images is unaffected by attentional resources, as manipulated by the cognitive load produced by the N-back task.

    Journal Title

    Visual Cognition

    Volume

    22

    Issue/Number

    3-4

    Publication Date

    1-1-2014

    Document Type

    Article

    Language

    English

    First Page

    522

    Last Page

    547

    WOS Identifier

    WOS:000334070000015

    ISSN

    1350-6285

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